This invention patent relates to a retractile needle meat pieces injecting machine, which has a series of improvements in its general structure sustaining the attainment of important advantages with respect to equipment applied to the same purpose now existing in the market.
These machines, as it is well known, are used to condition meat, being usually employed in the pork industry (for instance in the York ham and other similar products manufacturing), in order to enrich the treated meat or improve its presrvation conditions, by means of the addition to it of products such as brine, proteins, phosphates, and similars.
The fact of being provided with retractile needle groups comes from the preferential use of this kind of machine for the treatment of meat products having bone, being in this case necessary take into account that when the needle carrier head is lowered on the product can these needles, finding an obstacle in its penetration through the meat mass, individually go back in appropriate manner. Up to date the most usual solution to this purpose has been to provide the needle carriers with springs allowing its relative movement with respect to the carrying head.
However, given the fact that the injection of these products to the treated meat must be obviously performed in the most homogenous way, without dead spaces or spots throughout the piece subjected to the treatment, it can be understood the need of having heads with a high number of very near needle rows, which periodically are lowered into the meat piece while the latter is in its turn progressively travelling on a transport base in a co-ordinated way with the head action. Now then, since every injection needle must be connected to a supplying pipe for a fluid pressure driven by means of a pump and the needles being mobile, it is necessary to provide a series of flexible pipes to connect the supplying orifice with each needle, which determines, given the required nearness of the needles, that the number of such elements parallel rows (usually quincunx-arranged) be limited to two. So it can be seen in the embodiment foreseen by the applicant company in its Spanish Pat. No. 399,743.
As an option, the applicant has also proposed in its Spanish Pat. No. 234,805 an alternative to the aforementioned problem, replacing the manifold and the pipes by a long-shaped tank, arranged horizontally and transversly to the head, the ducts of the fluid to be injected being connected to its side ends, being provided in its lower horizontal wall with a series of holes through which pass rigid vertical tubes entering inside the tank and having a helicoidal spring associated with each one, these tubes being the needle carriers.
The use of springs linked to needle carrier tubes inside the tank containing the fluid to be injected has, however, proven be inefficient, making necessary a number of requirements in the materials to be used, maintenance requirements, and also functional ones, which make this solution not advisable.